Just logged in because I need to rave about this device. Bought my ES100 second-hand for around €40 about 18 months ago, and it is still working flawlessly.
It's the most robust Bluetooth device I've ever used, connects every single time, auto-powers down when I forget to turn it off, and the battery lasts forever. Seriously, I think I only charge it like once every other week and it's always ready to go, even if it's been laying in a bag for like a month. It sounds amazing. Even works via USB with my laptop. EQ isn't parametric but is fine for when I'm on the go.
Honestly it's a better user experience for me than using AirPods and that's saying something(!)
It is without a doubt the best audio purchase I've ever made, considering what I got for my €40. Props to Radsone.